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Search for positive interference between different QGP-signatures (what is cat?)

Objectives. Search for positive interference between different QGP-signatures (what is cat?) Initial & Intermediate reaction stage (life instead of archaeology). Stavinskiy,ITEP,9.04.08. Why  ?(common part).

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Search for positive interference between different QGP-signatures (what is cat?)

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  1. Objectives • Search for positive interference between different QGP-signatures (what is cat?) • Initial & Intermediate reaction stage (life instead of archaeology) Stavinskiy,ITEP,9.04.08

  2. Why  ?(common part) Themeson was proposed in the middle of 80’(Koch,Muller,Rafelski PR142,ShorPRL54) as one of the most promising QGP messengers because of the following reasons: • an enhancement of –meson, as well as other strange hadrons in QGP phase • interaction cross section is small and will keep information about the early hot and dense phase • meson spectrum is not distorted by feeddown from resonance decays • strangeness local conservation for  Stavinskiy,ITEP,9.04.08

  3. Why  ?(original part) • Femtoscopyfor rare but most informative modes •  mesons • Femtoscopy for particles with purity ~ 100% • Femoscopy for particles with cτ~ r (new promising domain for femtoscopy) • High mt meson femtoscopy (meson-baryon) • Residual & background correlations under control • Branching ratiosas an instrument for density integral measurements • mesons ( mesons) • new source of information • Interplay between different ALICE subdetectors(?) Stavinskiy,ITEP,9.04.08

  4. 1. φ meson femtoscopy Stavinskiy,ITEP,9.04.08

  5. Interferometry p1 r1 Bose-Einstein statistics of identical bosons leads to short-range correlations in momentum space r2 p2 First application with photons: size of stars (R. Hanbury-Brown, R.Q. Twiss, 1956) Δp In heavy-ion reactions: pions, kaons, φ-mesons… Stavinskiy,ITEP,9.04.08

  6. Geometric substructure? random system: all observers measure the “whole source” Stavinskiy,ITEP,9.04.08 malisa - SPHIC - Catania Italy - Sept 2006

  7. Flow-generated substructure • Specific predictions ofbulk collective flow: • space-momentum (x-p) correlations • faster (high pT) particles • come from • smaller source • closer to “the edge” Stavinskiy,ITEP,9.04.08 malisa - SPHIC - Catania Italy - Sept 2006

  8. Pratt-Bertsch parameterization Decompose q into components: qLong: in beam direction qOut : in direction of transverse momentum KT qSide:  qLong & qOut Radii are related to source variances: Sensitive to emission time Sensitive to transverse extent Sensitive to longitudinal extent In Longitudinally Co-Moving System (LCMS) bl =0 Stavinskiy,ITEP,9.04.08

  9. Energy Scan • Measurements at 200, 130, 62 GeV • No significant change with energy from AGS to RHIC • Ro/Rs ~1 Puzzle #1 Is HBT sensitive to geometry at all?! Stavinskiy,ITEP,9.04.08 PHOBOS nucl-ex/0409001

  10. t Particle species dependence RHIC-PHENIX: Au+Au sqrt(SNN)=200GeV [M. Heffner J., Phys. G 30 (2004) S1043-S1047], [nucl-ex/0510014] • an approximately “universal” mTdependence is usually attributed to collective flow • KK one dimensional radius 3-5 fm K.Mikhaylov,A.Stavinsky ITEP PWG2, Alice Week, CERN 31March2008 12

  11. Kaon femtoscopy CERN-SPS:Pb+Pb at 158 AGeV/c [PRL,87(2001)112301] RHIC-STAR: Au+Au sqrt(SNN)=200GeV K+K+ [Phys.Rev.C 74 (2006),054902] K0SK0S R = 4.09 ± 0.46(stat.) ± 0.31(sys) fm and λ = 0.92±0.23(stat)±0.13(sys) at the mean transversemass <mT> = 1.07 GeV. The duration time Δτ=sqrt(r2out-r2side)/β= 2.2± 5.2(stat.) ± 5.1(sys) fm K.Mikhaylov,A.Stavinsky ITEP PWG2, Alice Week, CERN 31March2008 13

  12. K+ Mothers One event PbPb@5.5 TeV HIJING (galice.root)‏ K+direct 38% KK*(892)0 35% KK*(892)+ 19% KΦ 8%, it is two times better than π+ (π+prim/π+all =19%)‏ K.Mikhaylov,A.Stavinsky ITEP PWG2, Alice Week, CERN 31March2008 14

  13.  0 } residual correlation 0  • Distance between  ~107 fm • No interference , but correlation • due to interference  15 Example of residual correlations R (Q = N real*R(Q )/N mixed R= 1+exp(-Q2r02), • - correlation strength, Q- invariant relative momentum, r0- source size • Mixed means from different events Stavinskiy,ITEP,9.04.08

  14. NA49: K+K- correlations in PbPb at 158AGeV nucl-ex/0210018 Stavinskiy,ITEP,9.04.08

  15. C L A S p r e l i m i n a r y Stavinskiy,ITEP,9.04.08

  16. Φ(1020) K+ K-B.R. 0.49 c = 44 fm Φ(1020) e+e-B.R. 0.000296 c = 44 fm d+Au PHENIX Φ K+K- STAR Preliminary √sNN = 200 GeV Au+Au PHENIX Φ e+e- √sNN = 200 GeV Stavinskiy,ITEP,9.04.08

  17. correlations iii R (ij jjj • Intensity of correlation  • S/B ratio ( N4 totally~10-2 with respect to pions (kaons) correlations Stavinskiy,ITEP,9.04.08

  18. Expected results • New data to understand RHIC HBT-puzzle • Droplets with hidden strangeness • High mt meson femtoscopy • Correction for kaon femtoscopy • First glance into initial reaction stage • Femtoscopy for resonances with cτ~r Stavinskiy,ITEP,9.04.08

  19. 2.Different φ and ωdecay modes absorption Stavinskiy,ITEP,26.03.08

  20. Upper line – lepton mode Splitting – two hadron and hadron-photon modes l -decay products trajectory length within matter φ β= 1/3 ω Stavinskiy,ITEP,9.04.08 l,fm

  21. ΦProduction K+K- and e+e- e+e- K+K- • The leptonic channel yield is a little higher than hadronic channel • More accurate measurement is required to confirm whether there is branch ratio modification Stavinskiy,ITEP,26.03.08

  22. ω(782) π+ π-π0B.R. 0.89 c = 23 fm ω(782) π0 B.R. 0.089 c = 23 fm η(547) π+ π-π0B.R. 0.23 c = 167225 fm PHENIX η,ω π+π-π0 p+p Au+Au p+p ω π0 PHENIX √sNN = 200 GeV ω π0 PHENIX

  23. Φ information early stages of the collision • Φ  different production for hadronic and leptonic channels • K*  time between chemical and kinetic freeze-out π K* K K* measured π K* K*lost K π K* π π K* K K K K* measured S. Pal et al., Nucl.Phys. A707 (2002) 525-539 • If resonance decays before kinetic freeze-out  not reconstructed due to rescattering of daughters • K*0(c = 4 fm)survival probability timebetween chemical and kinetic freeze-out, source size and pT of K*0 • Chemical freeze-out elastic interactionsπK  K*0 πKregenerate K*0(892)until kinetic freeze-out • K*0/K may reveal time between chemical and kinetic freeze-out Chemical freeze-out Kinetic freeze-out

  24. STAR K*  Ratios Chemical freeze-out Kinetic freeze-out Chemical = Kinetic freeze-out • K*/K- p+p ratio reproduced by thermal model at chemical freeze-out  Au+Aureproduced by thermal model at kinetic freeze-out

  25. Real σMN in matter can differ from that in free space • ω photoproducton on nuclear targets (ELSA) M.Kotulla et al., ArXiv: nucl-ex/08020980 σωN ≈ 70 mb (in nuclear medium, 0.5 < P <1.6 GeV/c) σωN ≈ 25 mb (in free space - the model calculations) •  photoproducton on nuclear targets T.Ishikawa et al., Phys.Lett.B608,215,(2005) σφN= 35 ± 14 mb (in nuclear medium) σφN ≈ 10 mb (in free space) “φ-puzzle” photoproducton on nuclear targets

  26. Teams (open draft ) •  meson femtoscopy • K.Mikhailov(ITEP)-analysis procedure,realistic simulation within AliRoot(AliFemto) • B.Batyunya(JINR)-PID for  (kaon and lepton modes) • L.Malinina(MSU)-event generator for fast MC,K+K- • S.Tolstoukhov(MEPI,ITEP)-realistic simulation within AliRoot(AliFemto) • R.Lednicky(JINR)-theoretical support(?,K+ Ks) • A.S. •  meson branching ratios • V.Fedotov(ITEP) analysis procedure for ideal detector for η mode • A.S. Stavinskiy,ITEP,26.03.08

  27. Status

  28. Some aspects of KK femtoscopy in ALICE Konstantin Mikhaylov and Alexey Stavinskiy ITEP, Russia ` K.Mikhaylov,A.Stavinsky ITEP PWG2, Alice Week, CERN 31March2008 30

  29. Measured space-time extent of the particle emitting region for KK is pure than for ππ. Kaon femtoscopy signal is cleaner than pion femtoscopy signal since Kaons are less affected by resonance decay. The mT dependence: mT(KK) > mT(ππ). The strangeness distillation mechanism could lead to strong temporal emission asymmetries between kaons and anti-kaons [S.Soff et al., J.Phys.G23,2095(1997);D.Ardouin et al.,Phys.Lett.B446,191(1999)]. Due to the highest branching ratio of Φ meson is KK the ΦΦ residual correlations could be seen from KK correlation function. Physics motivation K.Mikhaylov,A.Stavinsky ITEP PWG2, Alice Week, CERN 31March2008 31

  30. Aliroot v4-10-Rev-02 AliFemto from svn/trunk Local analysis of 650 events PDC2007: HIJING PbPb 5.5 TeV 1D K+K+ correlations 0.1 < PT < 1.0 GeV/c Anti-splitting cut Gaussian distr.: d3N/d3r*~ exp(-r*2/(4r02))‏ K+K+ r0:2 and 5 fm Source size for kaons from K* decay (vτ=2.6fm)‏ Simulations: software and input K.Mikhaylov,A.Stavinsky ITEP PWG2, Alice Week, CERN 31March2008 32

  31. PID study // e, mu, pi, K, pDouble_t c[5]={0.064,0.089,0.82,0.075,0.086}; π K p K.Mikhaylov,A.Stavinsky ITEP PWG2, Alice Week, CERN 31March2008 33 K.Mikhaylov,A.Stavinsky ITEP Alice Week, CERN 31March2008 33

  32. Pair PID 100 events PbPb@5.5 TeV HIJING QINV<0.25GeV/c KdirKdir7% 7222( 6.95165%)‏ KdirKK*0 15298( 14.7253%)‏ KdirKK*+ 7652( 7.36555%)‏ KK*0KK*+39% 8181( 7.87475%)‏ KK*+ KK*+ 2067( 1.98962%)‏ KK*0 KK*0 8077( 7.77464%)‏ KdirKΦ 3129( 3.01187%)‏ KΦKΦ 345( 0.332085%)‏ KK*0(KK*+)KΦ 5022( 4.83401%)‏ Other exotic (KdirKD0,...) 1352( 1.30139%)‏ (KK)fake 46896( 45.1405%)‏ Total 103889 (100%)‏ 45% K.Mikhaylov,A.Stavinsky ITEP PWG2, Alice Week, CERN 31March2008 34

  33. Remove splitting (r0=5fm) Splitting(merging) of tracks can change experimental CF at low QINV No anti-splitting cut With anti-splitting cut K.Mikhaylov,A.Stavinsky ITEP PWG2, Alice Week, CERN 31March2008 35

  34. Test various source size With Anti-Splitting cut No anti-splitting cut With anti-splitting cut 2fm 5fm K.Mikhaylov,A.Stavinsky ITEP PWG2, Alice Week, CERN 31March2008 36

  35. Source “expansion” due to K* Both K are direct • KdirKdirsource size is smaller than KdirKK* due to K* decay length • Assume K* source size the same as KdirKdir (r0)‏ • Measured source in second case: sqrt(r02+(vτ)2)‏ • Estimate v form K* spectrum (vτ~2.6 fm)‏ K r0 K One K is direct and the other one from K* decay K rmeasured K K*(cτ=4fm)‏ π K.Mikhaylov,A.Stavinsky ITEP PWG2, Alice Week, CERN 31March2008 37

  36. K+K+ correlation function(r0=5fm)‏ Source “expansion” due to K* decay (r0=5fm, K* vτ ~ 2.6fm)‏ K+K+ source size was: 1. Both K+ are direct r0=5fm 2. One K+ is direct and one from K* r0=sqrt(52 + 2.62) = 5.6fm 3. Both K+ from K* r0=sqrt(52 + 2.62 + 2.62) = 6.2fm 4. Also some small amount of K+ came from Φ meson, but it is small effect ‏ K.Mikhaylov,A.Stavinsky ITEP PWG2, Alice Week, CERN 31March2008 38

  37. Space distribution (r0=5fm)‏ Source “expansion” due to K* decay (r0=5fm, K* vτ~2.6fm)‏ 5 fm→5.7 fm K.Mikhaylov,A.Stavinsky ITEP PWG2, Alice Week, CERN 31March2008 39

  38. K+K+ correlation function(r0=2fm)‏ ‏ Source “expansion” due to K* decay (r0=2fm, K* vτ ~ 2.6fm)‏ K+K+ source size: 1. Both K+ are direct r0=2fm 2. One K+ is direct and one from K* r0=sqrt(22 + 2.62) = 3.3fm 3. Both K+ from K* r0=sqrt(22 + 2.62 + 2.62) = 4.2 fm 4. Also some small amount of K+ came from Φ meson, but it is small effect ‏ K.Mikhaylov,A.Stavinsky ITEP PWG2, Alice Week, CERN 31March2008 40

  39. Space distribution (r0=2 fm) Source “expansion” due to K* decay (r0=2fm, K* vτ~2.6fm)‏ 2 fm→3.1 fm K.Mikhaylov,A.Stavinsky ITEP PWG2, Alice Week, CERN 31March2008 41

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